Safety tread for bath equipment floor



March 17, 1964 c. s. TREACY SAFETY TREAD FOR BATH EQUIPMENT FLOOR Filed Sept. 26, 1962 FIG. I,

FIG. 2.

FIG. 3.

22 INVENTOR CYRIL s. TREACY ROBERT CALVERT ATTORNEY.

United States Patent 3,124,811 SAFETY TREAD FOR BATH EQUIPMENT FLGGR Cyril S. Treacy, 164 Boulevard, Scarsdale, N.Y. Filed Sept. 26, 1962, Ser. No. 226,378 3 Claims. (Cl. 4-173) Tihs invention relates to safety tread for bathtubs, shower stalls or the like.

The invention is particularly useful for bathtubs and will be illustrated by description in connection therewith.

Danger of accident to persons from slipping in bath equipment is well known and has received much attention. Closely spaced ridges or uneveness of surface in the bottoms of the tubs have been formed, as by varying the thickness of the metal construction. Insofar as known to the applicant, these have not been successful and the expedient most used at this time is a rubber mat or other removable antislip device laid in the bottom of the tub. Among other disadvantages is retention of water underneath the device when the tub is emptied.

The present invention provides a permanent antislip tread without the necessity of changing the molds or other major equipment used in casting the iron tubs or finishing them in enameled form. Furthermore, the invention provides a structure that may be of architectural value, as by being ornamental in pattern or color variation.

Briefly stated the invention comprises the herein described product and process of permanently bonding antislip elements at closely spaced intervals to the enamel of the bottom of a bathtub or to the cement fioor of a shower bath. In the preferred embodiment the invention comprises setting the antislip elements on the enamel coating of the surface to be provided with the tread before the enamel is fired and then firing the assembly so that the enamel, in fusing and subsequently solidifying, bonds said elements in permanent position and water resistant condition.

The invention is illustrated in the drawings in which FIG. 1 is a side view partly broken away for clearness of illustration of a bathtub equipped with the antislip tread;

FIG. 2 is a plan View of the tub of FIG. 1;

FIG. 3 is a vertical section showing in greater detail the antislip elements embedded in the enamel of the bathtub bottom; and

FIG. 4 is a like view 'of a modification in which the antislip elements are adhered by .a waterproof adhesive to the enamel of the bathtub.

In the various figures, the thickness of the layers of enamel or adhesive is exaggerated.

There is shown the bathtub with drain 12, floor or bottom 14 and antislip elements 16 disposed above the floor and secured by the enamel 1:8.

The enamel suitably extends a short distance upwardly around the edges of the several antislipping elements as illustrated at 20 in FIG. 3 for the purpose of improving anchorage of the elements in position.

In the modification shown in FIG. 4, the adhesive layer is 22.

The tubhas a door that, although it may curve somewhat in certain areas at least, is substantial-1y planar.

In providing the tub with the antislip tread of type described, the tub of cast iron or other material is formed and the enamel 18 is applied in any conventional manner. Thus the iron is cast and, after cooling, is sprayed upon the bottom and inside the walls first with a ground coat of the enamel in relatively thin condition. A series of somewhat thicker aqueous dispersions or pastes of the enamel solids are then applied. After each application (of ground or cover coat), the coat is dried, the next coat is applied, again dried, and the process repeated until ice the proper amount of the enamel mixture has been applied on the wall and floor of the bath tub. Then the antislip elements, which may be described as buttons, are placed in position over the enamel composition. Suitably these buttons are coated on their backs with a layer of the same composition as that applied originally as ground coat or a later coat to the tub. The buttons in any case, are placed upon the coated floor of the tub, in the portion to constitute the antislip tread, and pressed firmly thereagainst. The said elements may be arranged in any pattern desired, as by being placed in the openings in a templet of convenient kind resting upon the floor, with the templet to be withdrawn when all of the buttons are above the spots on which they are to rest.

Then the tub, with the discs or other shapes of the buttons in place, is subjected to firing in usual manner and equipment, care being taken not to dislodge the buttons from their respective positions in the arrangement desired. When the whole has been fired the tub is removed from the furnace and cooled, all by customary technique. It will be found that the antislip elements are firmly anchored at their backs in the fired enamel of the tub, with their faces or upper surface left unglazed, so as to increase the slip resistance.

To improve further the anchorage of the antislipping discs in the enamel, the enameling paste may be applied to the lower parts of the side edges of the separate antislip elements, as by a fine spray or brush before the firing is undertaken, so that a portion of the enamel on such sides becomes integral, during the firing, with the enamel of the bottom of the tub.

The shapes of the antislip elements, sometimes referred to as buttons or plates, may be of any shape desired, e.g., of circular face, square, elliptical, or irregular. Their upper surface may be plane or convex and their side edges vertical or rounded.

As to size, the total area involved in the antislip surface of the bottom of a bathtub is about that on which the feet normally stand as the user enters or leaves the tub or stands in the shower stall. This area may be about 1x2 feet in the tub and 3x3 feet or more in the stall.

The individual elements that collectively provide the antislip effect may be varied to suit desires of the user, as, for instance, in the range 0.05-0.5 inch and ordinarily about 0.1-0.3 inch in thickness, 0.3-1.5 inch and usually about 0.51 inch in diameter (or shortest distance across) and spaced on centers about 1.5-3 times the diameter. For most persons it is recommended that the faces of the antislip elements cover at least about a fourth to threefourths of the total surface of the area to which they are applied. Thus discs of 0.5 inch diameter and 0.2 inch thick may be set on 0.75 inch centers.

Area between the upstanding antislipping elements and the enameled tub floor is at the level of the bottom of the tub so that drainage is unrestricted.

Materials that are used are those that are conventional except as noted herein. Thus the structural material of the tubs may be made of cast iron, ceramic ware or the like. The rigid antislip elements may be of any composition such as ceramic that is resistant to heat distortion at the temperature of firing the bathtub with the applied enamel, i.e., it must be of higher softening or heat distortion temperature than the softening or glaze point of the enamel. Said elements should be of coelficient of thermal expansion varying by not more than about a third from that of the enamel coating in fused and then solidified condition, generally unabsorptive of water and free of objectionably sharp, protruding particles. Elements of pottery, china, or porcelain Ware, or clay and sand mixture in fired condition are satisfactory. So also are the hexagonal or other tablets of earthenware or other ceramic compositions commonly laid with a generally level surface in bathroom floors.

The enamel on the surface to which the antislip elements are to be bonded is any one that is used commercially in enameling bathtubs.

The invention will be further illustrated by the following specific examples, proportions here and eleswhere herein being expressed as parts by weight.

Example 1 The selected ingredients for the enamel are each finely ground, mixed thoroughly, fritted by heating in a furnace to molten condition, tapped, quenched by being dropped in water, and then dried and ground again to a fine powder. For application to the walls of the bathtub or the like, the resulting powder is slurried With water, either to the thin consistency desired for application by spraying as the ground coat on the walls of the tub or, with a smaller proportion of water, to the thicker consistency for cover coats to be applied over the dried ground coat and eventually over each other, in building up the necessary thickness of the dried enamel coats.

Examples of the solid components of the enamel compositions for the ground coat on cast iron and for subsides as used) of discs of the antislip elements, in order to promote bonding of them in the enamel during the subsequent firing and cooling.

The firing of the tub, with the coating to constitute the finished enamel and with the antislipping elements in position on the coating, is conducted at temperatures usual for such firing and glazing of the enamel but below the temperature of heat distortion of the antislip elements, as, for instance, at about 1300-1550 F. at the maximum, the total heating period being approximately one-half hour.

After the firing is completed cooling is effected in air. As the enamel thickens and approaches solidification, the antislip elements are gently but evenly pressed against the enamel, as by a smooth stainless steel plate with vertical handle, as a further assurance of proper leveling of the elements. They will then extend upward to about the same distance above the bottom of the tub.

Example 2 In the modification of this invention illustrated in FIGURE 4, the tub and enamel are fired and completed in regular manner before the antislip elements are applied. The elements are then applied with an adhesive that when set is water resistant, so that the bond is not loosened by soaking in either hot or cold water. Thus the discs or buttons of kind described above are coated Cir with the adhesive over their backs (the surfaces that are to be adhered to the previously fired enamel) and the buttons are then placed in their desired position, as by means of the spacings in a templet. The templet is removed and the buttons are pressed firmly and level against the enameled bottom of the tub, as by means of a hand roller moved cautiously over the buttons or a plate of kind described.

An example of a suitable resin for this use is an epoxidized polyphenol or polyhydric alcohol with an admixed curing agent therefore, e.g., the diglycidyl ether of hisphenol A (2,2-bis(p-hydroxyphenyDpropane. The curing agent, admixed just before use, may be and suitably is diethylene triamine or like polyamine, in the amount of about 5%30% of the weight of the said resin, proportions of other curing agents that are employed in the art of curing epoxy resins being satisfactory.

After the antislip elements are in position on the surface of the enameled bathtub, they are allowed to stand without application of water for about 10-24 hours, after which the discs cannot be slipped by hand or foot pressure or soaked loose by water, either cold or boiling.

A small amount of the epoxy resin and curing agent may be sprayed or brushed around the lower parts of the edges of the upstanding antislipping elements, to improve the seal and close any space that may exist between the adhesive and either the bottom of the tub or said element.

Another adhesive that illustrates the class to be used is the condensation product of about 1 mole of resorcinol with 0.9 mole of 37% aqueous formaldehyde solution in acid medium. This is mixed at the time of use with about 10 parts of hexamethylene tetramine as curing agent for 100 parts of resin solids. The resin and curing agent may be applied separately to the opposed surfaces to be joined.

The antislip treads are easily applied and are effective in providing the desired slip resistance to the human foot resting thereupon.

It will be understood that it is intended to cover all changes and modifications of the examples of the invention herein chosen for the purpose of illustration which do not constitute departures from the spirit and scope of the invention.

I claim:

1. A bathtub comprising a floor of substantially planar upper surface, a glazed enamel coating thereover, and preformed antislip elements, said elements being in the form of plates of thickness about 0.050.5 inch and of shortest dimension across the face thereof about 0.3-1.5 inches, disposed in spaced relationship to each other and bonded at their backs to the surface of said coating.

2. The bathtub of claim 1, said elements being nonsoftening at the temperature of softening of the coating and the bonding to said coating being ceramic.

3. The bathtub of claim 1, the bonding of said elements to said coating being efiected by an adhesive that is non' loosening on being soaked in hot water and is selected from the group consisting of epoxidized polyphenols and epoxidized polyhydric alcohols.

References Cited in the file of this patent UNITED STATES PATENTS 2,045,867 Mueller June 30, 1936 2,292,368 Gordon Aug. 11, 1942 FOREIGN PATENTS 422,995 Great Britain Jan. 23, 1935 

1. A BATHTUB COMPRISING A FLOOR OF SUBSTANTIALLY PLANAR UPPER SURFACE, A GLAZED ENAMEL COATING THEREOVER, AND PREFORMED ANTISLIP ELEMENTS, SAID ELEMENTS BEING IN THE FORM OF PLATES OF THICKNESS ABOUT 0.05-0.5 INCH AND OF SHORTEST DIMENSION ACROSS THE FACE THEREOF ABOUT 0.3-1.5 INCHES, DISPOSED IN SPACED RELATIONSHIP TO EACH OTHER AND BONDED AT THEIR BACKS TO THE SURFACE OF SAID COATING. 